Integrated trench capacitors are known for high density capacitor designs. Formation of an integrated trench capacitor generally involves forming a deep trench type structure in a highly doped silicon substrate, lining the sidewalls and bottom of the trench with at least one dielectric layer, usually silicon oxide, followed by polysilicon filling of the trench that is doped in-situ or doped after the deposition, and then patterning of the polysilicon layer.
Capacitors and inductors formed on electric circuits including ICs are not ideal components because they do not have only capacitance or only inductance. However, they can be treated, to a good degree of approximation, as being ideal capacitors or ideal inductors in series with a resistance defined as being the equivalent series resistance (ESR).